People who lack sufficient Level 2 abilities will have trouble with a classical college education. This is also not surprising, given that you need to reason and solve problems to get a degree in history, economics, or chemistry.
I'm not at all surprised by
Academically Adrift's finding that people who majored in business and other easier subjects didn't score well on tests of complex reasoning skills. If they lacked sufficient Level 2 abilities to begin with, the finding isn't surprising. Alternatively, they wouldn't have picked a major that required complex reasoning ability (this idea reminds me of a recent thread about people leaving STEM majors because they're "too hard." They are too hard for a lot of people!). I'm sorry to say that education majors are in the lower-performing group.

Based on this information, the idea that there is a minimum IQ for getting through a college degree in more traditional subjects makes perfect sense.